Auxiliary spring



Feb. 19, 1935. W, SAMUELS 1,991,580

I y AUXILIARY SPRING Filed Jan. 4, 1934 y /4 (29. 2 Wil/fm 5MM/f Patented Feb. 19, 1935 William Samuels, Detroit, Mich., assigner to Geny eral Motors Corporation, Detroit, Mich., a corporation of Delaware Application January 4, 1934, Serial No. 705,168 2 claims. (c1. 267-45) This invention has to do with Vehicle springY clamp plate 5, secured to the axle 2 by a pair of suspension. In the case of heavy duty trucks, for U-bolts 6, embracing a split axle block 7. The example, the practice has beento provide a very axleshown in the drawing is of the driving type stiff spring designed particularly to take care and carries at'opposite ends a pair of road wheels 5 of maximum load requirements with the result 8, only the farther one of which is shownV in the 5 that a rough ride is had when the load is light. drawing., To afford a smooth and comfortable ride through-` Extending longitudinally of the frame in verout the load range, it is here proposed to provide tical alinement with the main load supporting a duplex spring arrangement involving a main spring 4 is the helper spring assembly, which inload supporting spring for action at all times, but cludes a multiple leaf spring 9, supported by and 10 more resilient than the conventional heavy duty connected at opposite endstothe chassis frame spring, to give a soft ride for light loads and a .bya pair of frame vbrackets 10, riveted orotherhelper spring which comes into action to carryY Wise secured in place. The underside of each a portion of the load after a given deflection of bracket 1.0 is provided with a curved or arcuate the main spring. Thus the supplemental spring bearing surface 11 for engagementlwith the top i5 is out of play and the main spring alone carries of the main leaf of thespring pack 9. Engaging a light load, while the combined resistance of the underside of the spring leaf is a rounded both springs is available for heavy loads., surface 12 on a nut 13, which is secured by a lock An important feature of the present construcnut 14 on a threaded stud 15 extending upwardly 2O tion is that it has been designed especially with through an opening in the spring and into 20 the view of eliminating need for material alterathreaded engagement with a recess in the bracket tion and rearrangement of conventional parts, 10. The curved surfaces 11 and 12 thus provide which is to say, the main load supporting spring oppositely flared bearings which receive the is connected with the chassis frame and axle, as spring therebetween and provide for easy rocking in the past, but there has been added a helper Iof the spring end upon spring deflection. 25

spring assembly which can be easily and conven- In the case of the connection for one end of the iently mounted wholly on the chassis frame and spring, as shown in detail in Figure 2, the opening free of direct connection with the axle. As so in the spring that receives the attachment stud incorporated inthe chassis frame, the opposite is only slightly larger than the diameter of the ends of the helper spring are held in a'manner to stud while the opening in the opposite end of the 30 accommodate exing of the spring when an interspring consists of an elongated slot as in Figure mediate portion thereof, spaced from the axle in 3 to permit relative movement upon spring the unloaded position of the parts,ris engaged elongation. Thus while lthe connection at one by the axle after a given deflection of the main end permits relative rocking andlongitudinal spring. The construction'enables easy convermovement, the connection at the opposite end 35 sion of a light duty truck for heavy duty work, accommodates rocking movement only and lo-l without disturbing the original spring assembly. cates the assembly against displacement.

A better understanding of the invention can be At an intermediate point and directly above had from the accompanying drawing, wherein the plate 15, the helper spring 9 carries a bumper Figure 1 is a fragmentary view showing in side 16 in the form ofa plate, having a downwardly 40 elevation a portion of a vehicle chassis frame extending rounded boss which in the unloaded supported through springs from an axle shown in position of the parts, as shown by full lines in section, andFigures 2 and`3 are detail views with the drawing, `is spaced considerably above and parts in section, showing the connections for opout of engagement with the plate 5. In this relaposite ends of the helper spring. tion of parts the main spring 4, as is obvious, 45

Referring to the drawing, the reference nutransmits the full load of the chassis framel to meral 1 indicates one of a pair of side bars of a the axle 2. However, upon application of load, chassis frame, both of which Vare flexibly mounted the main spring 4 is deflected and when the parts uponan axle 2 by the spring arrangement to' be move to the position indicated by broken lines in described. Each side bar carries a pair of longi- Figure l, the bumper 16 is brought into engage- 50 tudinally spaced brackets 3, by which is connected ment with the plate 5 and thereafter a partY of the opposite ends of amultiple leaf semi-elliptical the load is carried by the helper spring 9 and spring 4, which constitutes the main load suptransmitted directly to the axle through the rigid porting spring.` At an intermediate point the mounting of the main spring thereon. 'Ihus spring 4 is engaged on its upper surface by a both springs cooperate to carry heavy loads, but 55 the resistance of one is eliminated to give a smoother ride when the vehicle is lightly loaded.

I claim:

1. In a vehicle, a main load supporting spring, a secondary spring adapted to assist in supporting load after a predetermined load application, a pair of spaced frame brackets each having a longitudinally curved surface for progressive engagement with the' opposite ends o f the secondary spring upon flexure thereof, headed locating studs projecting from said surfaces and passing through openings in the spring ends, one of which opention, and a bumper carried intermediate the ends of said secondary spring.

2. In a vehicle, a main load supporting spring,v l

a helper spring associated therewith and adapted for action after a given loading o! the mainV spring, a pair of mounting brackets for oppositeV ends of the helper spring each having a pair of oppositely flared bearing surfacesengaging oppositefaces of the spring end, and a bumper carried by the helper spring intermediate its ends through which deecting force is received. Y f

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